&CELL: ROWS
States that the wires will be entered in Cartesian coordinates,
(x,y).
This keyword need not be specified if the cell is already
established to be in Cartesian coordinates, for instance if
a plane at constant x has already been entered. This keyword
is not valid if the cell is already established to be in
polar or in tube coordinates.
When Cartesian coordinates are used, you may enter planes at
constant x and at constant y. Also both x and y periodicities
are permitted.
[If no coordinate system has yet been established when ROW is
entered, then Cartesian coordinates are assumed by default.]
States that the wires will be entered in polar coordinates (r,phi)
with r in cm and phi in degrees. When using polar coordinates, you
must ensure that no wire is located at r=0. If you need to describe
a cell which has a wire at the center of a round plane, then TUBE
should be used.
When the wires are listed in polar coordinates, the planes have to
be entered in polar coordinates too. That is, the planes can be
at constant r or at constant phi.
Periodicity in phi is permitted, but radial periodicity isn't.
These coordinates are transformed to an internal coordinates system
which is a conformal map of a Cartesian system - but all frequently
used instructions transform these internal coordinates back to
polar coordinates when outputting the results.
This keyword need not be specified if the cell is already
established to be in polar coordinates, for instance if
a phi periodicity has already been entered. This keyword
is not valid if the cell is already established to be in
Cartesian coordinates or in tube coordinates.
[If no coordinate system has been established yet when the
ROWS command is entered, then Cartesian coordinates will be
assumed by default.]
TUBE is a special coordinate system, halfway in between Cartesian and
polar. Tubes are used to describe for instance a wire running in the
middle of a round plane.
The tube itself and the phi periodicity, if any, is specified in polar
coordinates, but the wires are listed in Cartesian coordinates.
Like for polar coordinates, a coordinate transformation is applied to
the wire location but the internal coordinates never appear on output.
This keyword need not be specified if the cell is already
established to be in tube coordinates because a TUBE statement
has already been entered. This keyword is not valid if the cell
is already established to be in Cartesian or polar coordinates.
[If no coordinate system has been established yet when the
ROWS command is entered, then Cartesian coordinates will be
assumed by default.]
A single character identifying the wires in the row. You may give more
characters but only the first is relevant. These codes are used later
on to single out (groups of) wires that are in some way special. It's
worthwhile to choose the wire-codes well !
The number of wires in the row, this may be a symbolic expression in
terms of previously DEFINEd variables.
[Default: 1, i.e. a single wire].
The diameter of the wires in the row. This may be a symbolic
expression in terms of previously DEFINEd variables and you may use
the loop variable I in the expression if you wish.
[Default: 0.01 cm, i.e. 100 micron].
The x- or r-position of the wires in the row, this may be a
symbolic expression in terms of previously defined variables.
The loop variable I can be used to construct symbolic expressions
for the locations of the wires in the row. For instance, for a
series of wires with coordinates 1, 2, 3 and 4 you could enter
the expression 1+I.
[Default: 0 cm.]
The y- or phi-position of the wires in the row, this may be a
symbolic expression in terms of previously defined variables.
The loop variable I can be used to construct symbolic expressions
for the locations of the wires in the row. For instance, for a
series of wires with coordinates 1, 4, 9 and 16 you could enter
the expression (I+1)**2.
[Default: 0 cm, phi should be in degrees.]
The potential of the wires in the row, this may be a symbolic
expression in terms of previously defined variables.
The loop variable I can be used to construct symbolic expressions
for the potentials of the wires in the row. For instance, for a
series of wires with potentials 1000, 1000, 2000 and 2000, you
could enter the expression 1000+entier(i/2)*1000
[Default: 0 cm.]
The weight used to stretch the wires. Used to compute the
displacement of the wires under electrostatic forces.
[Default: 50 grams.]
The length of the wires. Used to compute the displacement
of the wires under electrostatic forces.
[Default: 100 cm.]
The density of the material of which these wires are made.
Used to compute the displacement of the wire due to gravitational
forces - not relevant if the wires are vertical.
For copper-Beryllium wires, one can also enter CU-BE and for gold
plated Tungsten one can type TUNGSTEN or W.
[Default: 19.3 g/cm**3, i.e. 20 micron gold plated Tungsten wire]
In earlier versions of the program, rows with a constant spacing
in the coordinates and the potential could be constructed using
increments (the 7th, 8th and 9th word).
This feature is much less powerful than the alternative method
using the loop variable and the increments have therefore been
suppressed as of version 5.
The loop-variable is a variable, named I, the program defines for
you and that takes on the value 0 for the first wire in the row,
1 for the second and so forth.
This variable may be used for the diameter, the position, the
potential, the stretching weight and the length of the wire.
The loop-variables can be used to construct non-standard electrode
shapes using wires. Some examples are shown in the description of
the wire position and voltage.
Keyword index.
Formatted on 10/11/98.